The present invention relates to a LAN interface. Particularly, the present invention relates to a LAN interface capable of reducing power consumption.
Recently, PC terminals, which have LAN interface functions as standard equipment, have been increasingly used for business users. However, some users may not always use the LAN connection. When a notebook-type personal computer (PC) is used outdoors, the case where the LAN function is not totally used occurs often. With the LAN interface attached, there is the problem that the battery power is wastefully consumed even in an idle state of the LAN interface. In the case of removal of the LAN interface, it is relatively easy to disconnect the PC card from the PC body. However, it is difficult or impossible to physically remove the LAN interface from the motherboard. Moreover, the problem is that every time the user goes out with the notebook-type PC, it has to be repeated to attach and detach the LAN interface to and from it.
The present invention is made to solve the abovementioned problems. An objective of the present invention is to provide a novel LAN interface capable of reducing the whole power consumption of a terminal at the time an LAN interface is not required.
In order to achieve the objective of the present invention, a LAN interface comprises a terminal connected to an I/O bus and a counter device connected to connection ports of the LAN interface. The LAN interface is connected to the I/O bus and transmitting and receiving a link pulse to confirm connection between the terminal and the counter device. The LAN interface includes a LAN controller for processing a signal transmitted from the terminal and then transmitting a processed signal to the counter device, and for processing a signal transmitted from the counter device and then transmitting a processed signal to the connection device; an isolation section connected between the LAN controller and the I/O bus, for electrically disconnecting the LAN controller from the I/O bus; an analog circuit connected between the LAN controller and the connection port, for subjecting a transmission signal and a received signal to an analog process; and a link pulse detector for operating on a predetermined voltage supplied via the I/O bus and detecting a link pulse from the counter device connected to the connection port. The link pulse detector, when detecting a link pulse output from the counter device, controls the LAN controller and the isolation section to controllably bring them to an operation state thereof. The link pulse detector, when not detecting a link pulse output from the counter device, controls the LAN controller and the isolation section to controllably bring them to a non-operation state.
In the LAN interface, the link pulse detector controls the power source potential of the LAN controller and the power source potential of the isolation section.
In the LAN interface, the link pulse comprises a signal on the basis of the IEEE 802.3 standards.
In another aspect of the invention, a LAN interface comprises a terminal connected to an I/O bus. The LAN interface is connected to the I/O bus. The LAN interface includes a LAN controller for processing a signal transmitted from the terminal and then transmitting a processed signal to a counter device, and for processing a signal transmitted from the counter device and then transmitting a processed signal to the connection device; an isolation section connected between the LAN controller and the I/O bus, for electrically disconnecting the LAN controller from the I/O bus; an analog circuit connected between the LAN controller and the connection port, for subjecting a transmission signal and a received signal to an analog process; and a frame detector for operating on a predetermined voltage supplied via the I/O bus and detecting the presence or absence of a frame, based on a signal from the counter device connected to the connection port. The frame detector, when detecting a frame, controls the LAN controller and the isolation section to controllably bring them to an operation state thereof. The frame detector, when not detecting a frame, controls the LAN controller and the isolation section to controllably bring them to a non-operation state.
In the LAN interface, the frame detector controls the power source potential of the LAN controller and the power source potential of the isolation section.
In further another aspect of the invention, a LAN interface comprises a LAN controller for processing a signal transmitted from a terminal connected to an I/O bus and then transmitting a processed signal to the counter device, and for processing a signal transmitted from the counter device and then transmitting a processed signal to the connection device; a separator connected between the LAN controller and the I/O bus, for electrically disconnecting the LAN controller from the I/O bus; and a link pulse detector for operating on a predetermined voltage supplied via the I/O bus and detecting a link pulse from the counter device connected to the connection port. The link pulse detector, when detecting a link pulse output from the counter device, controls the LAN controller and the isolation section to controllably bring them to an operation state thereof. The link pulse detector, when not detecting a link pulse output from the counter device, controls the LAN controller and the isolation section to controllably bring them to a non-operation state.
In the LAN interface, the link pulse detector controls the power source potential of the LAN controller and the power source potential of the isolation section. In the LAN interface, the link pulse comprises a signal on the basis of the IEEE 802.3 standards.
In still another aspect of the invention, a LAN interface comprises a LAN controller for processing a signal transmitted from a terminal connected to an I/O bus and then transmitting a processed signal to the counter device, and for processing a signal transmitted from the counter device and then transmitting a processed signal to the connection device; a separator connected between the LAN controller and the I/O bus, for electrically disconnecting the LAN controller from said I/O bus; and a frame detector for operating on a predetermined voltage supplied via the I/O bus and detecting the presence or absence of a frame based on a signal from the counter device connected to the connection port. The frame detector, when detecting a frame, controls the LAN controller and the isolation section to controllably bring them to an operation state thereof. The frame detector, when not detecting a frame, controls the LAN controller and the isolation section to controllably bring them to a non-operation state.
In the LAN interface, the frame detector controls the power source potential of the LAN controller and the power source potential of the isolation section.